This invention relates generally to high density polyethylene (HDPE) pipe fusion equipment and more particularly concerns equipment for feeding sticks of pipe into a machine for fusion to the trailing end of a pipeline.
Handling and staging sticks of pipe to be fed into a pipe fusion machine are presently labor intensive, time consuming tasks requiring use of expensive pipe loading, unloading and manipulating equipment and causing extensive downtime of the fusion machine while each stick of pipe is maneuvered into the machine and of the peripheral equipment while the fusion machine is in operation.
Typically, heavy construction equipment, such as telehandlers, backhoe loaders and fork trucks, are used to handle the sticks of pipe. Some pipe stands are available for use in the pipe fusion process, but they hold only one stick of pipe at a time and, despite use of the stand, other jobsite equipment is still required to load and position each and every stick of pipe in the fusion machine. More recently, a pipe storage rack has been combined with a single pipe stand, making it easier to load sticks of pipe onto the stand. It is not, however, an effective tool for manipulating sticks of pipe into a fusion machine. Furthermore, because of the pipe size, terrain contour and pipe loading limitations of this combination, there are many applications in which it is of little use at all.
Regardless of pipe stick diameter, joining sticks of plastic pipe to a pipeline by heat fusion requires loading the sticks of pipe, one at a time, into the fusion machine. Sticks of small diameter pipe, ranging up to about 6″ in diameter, can be loaded into the fusion machine by hand. Intermediate diameter sticks, ranging up to about 8″ in diameter, can be loaded by hand operated equipment. pipe handling equipment hereinbefore described facilitates loading of up to 20″ diameter pipe sticks by a single person but, as also disclosed, a power assisted option is useful for moving the 8″ to 20″ diameter sticks of pipe axially into the fusion machine.
Loading large diameter sticks of pipe, ranging from 8″ to 48″ in diameter, typically requires powered, heavy lifting equipment and normally requires two people, one operating the heavy lifting equipment and the other assisting in guiding the stick of pipe into the machine in response to hand signals between the operator and the assistant. Typically, the heavy equipment is a fork truck, a crane or a track hoe used like a crane.
A fork truck cannot be used to reposition the stick of pipe longitudinally. When the fork truck is used, hand signals from a spotter guide the equipment operator in repositioning the stick of pipe laterally and vertically with respect to the fusion machine. A crane can be operated to reposition the stick of pipe in any direction, including longitudinally, but the stick of pipe can spin and tip about the pickup point and, therefore, needs further guidance from someone on the ground. The person performing this task can also be the spotter, but the operation still requires at least two people and the commitment of the heavy equipment for relatively long periods of time during the pipeline fusion process.
Whatever heavy equipment is chosen, the process itself will be inefficient. Large sticks of pipe are delivered, one at a time, by trucks. Each stick must be lifted from the truck, set on the ground and later lifted from the ground and loaded into the fusion machine. The heavy lifting equipment and its skilled operator must be present throughout the day to load each stick of pipe into the fusion machine. The operator of the lifting equipment is not at a vantage point to see if the pipe is well aligned with the fusion machine, making the loading steps more tedious and time consuming or requiring the additional presence of a spotter. The outboard end of the pipe stick must be set on roller supports so that the pipe stick can move freely axially during the fusion process, but existing roller pipe supports are most often manually adjusted which, for large diameter pipe sticks, can be awkward. Often, the pipe stick is curved, requiring the roller pipe support to be manually re-adjusted for each stick of pipe to be aligned in the fusion machine. The cross sections of the sticks are often not exactly round. The ovality of the stick of pipe should preferably be matched to the pipeline ovality at the junction but, for large diameter pipe sticks, it is very difficult to rotate the stick of pipe to match the pipeline ovality.
It is, therefore, an object of this invention to provide a rack type pipe feeder for a pipe fusion machine which can stage multiple sticks of pipe. Another object of this invention is to provide a rack type pipe feeder for a pipe fusion machine which eliminates the need for dedicated heavy equipment to handle each individual stick of pipe. It is also an object of this invention to provide a rack type pipe feeder for a pipe fusion machine which requires heavy equipment only for the purpose of loading bundles of pipe from a truck onto the feeder. Still another object of this invention is to provide a rack type pipe feeder for a pipe fusion machine which is adjustable to accommodate variations in terrain contour. A further object of this invention is to provide a rack type pipe feeder for a pipe fusion machine which is usable with fusion machines of various sizes. Yet another object of this invention is to provide a rack type pipe feeder for a pipe fusion machine which usable with pipes of various sizes. An additional object of this invention is to provide a rack type pipe feeder for a pipe fusion machine which feeds pipe smoothly into a pipe fusion machine. It is also an object of this invention to provide a rack type pipe feeder for a pipe fusion machine which facilitates easy pulling of pipe through the jaws of the fusion machine into alignment for fusion with next stick of pipe. Still another object of this invention is to provide a means to rotate the pipe in order to match ovality.